Musculoskeletal (MSK) and orthopaedic disorders are staggeringly prevalent, disabling, and costly, accounting for ~5% of gross domestic product in the US. The COMET (Clinical Orthopaedic and Musculoskeletal Education and Training) T32 training program is focused on training clinical researchers to address the growing national and global burden of MSK disorders through rigorous clinical research. The COMET program has been highly successful in its first decade; 21 of its 25 graduates have remained in academic positions, with 8 receiving career development awards (5 K-level awards and 3 Rheumatology Research Foundation career development awards), and 5 R-level grants (3 R01s and 2 R21s). These 25 graduates have published 112 peer-reviewed papers based on their T32-funded work. Nearly 70% of current and former trainees are women and 3 belong to underrepresented minority groups. In this competitive renewal resubmission, we propose a programmatic focus on 6 research training concentrations that represent pressing research needs and draw on the strengths of the faculty: exercise and physical activity; orthopedic surgical outcomes; innovative non-pharmacologic trials; value-based care; work and MSK disorders; and MSK health in resource-limited settings. Trainees address these and related research themes in relation to a broad range of MSK and orthopaedic disorders, including osteoarthritis, osteoporosis, regional disorders (spine, knee, shoulder, upper extremity, foot/ankle), orthopaedic trauma, joint and soft tissue problems, nerve entrapments, chronic pain, and related conditions. Through their COMET training, young investigators acquire critical skills in biostatistics and epidemiology along with a range of other disciplines based on their career interests (e.g. behavioral science, economic analysis, clinical trials). Trainees without prior formal didactic training in these methodologies obtain a master's degree in the Clinical Effectiveness Program at the Harvard T.H. Chan School of Public Health. Drs. Jeffrey Katz and Elena Losina direct the COMET program and are supported by a highly experienced, productive, and collaborative group of faculty mentors from throughout the Harvard medical and public health communities. This application requests funding for two predoctoral and three postdoctoral training positions per year. This renewal resubmission application builds upon a foundation of success over the first decade of the program and is driven by the overarching goal of facilitating research to improve the quality of life of persons with debilitating MSK disorders.